1. Field of the Invention
This disclosure relates to semiconductor devices, and more particularly, to a method of manufacturing a semiconductor device that has contact bodies that extend in the bit line direction in order to contact storage nodes of a capacitor that are arranged in a zigzag manner in the word line direction.
2. Description of the Related Art
With advancements in techniques for manufacturing semiconductor devices, the sizes of transistors have decreased and the integration density of semiconductor devices has increased. Thus, the sizes of contact bodies used for electrical connection of layers have also decreased. Above all, in dynamic random access memories (DRAMs), forming capacitors in an 8F2-type strait active region becomes more complicated with the decrease in contact size. In a typical DRAM, in one plane, strait-type storage nodes of a capacitor are arranged in a lengthwise direction of an active region.
To meet a required capacitance, a typical DRAM includes a capacitor with cylindrical storage nodes, of which both the inner and outer surfaces can be used. However, highly integrated DRAM devices with a reduced design rule impede formation of a capacitor having a sufficient bottom critical dimension (CD). Thus, research for DRAMs securing a sufficient capacitance has progressed. An example is disclosed in U.S. Pat. No. 5,378,906 to Hee G. Lee, dated Jan. 3, 1995, entitled “Dynamic Random Access Memory having improved layout.”
Since the bottom of a storage node of a capacitor has a decreased CD, building cylindrical storage nodes that do not lean becomes very complicated. The leaning or the collapse of storage nodes results in contact fails between adjacent storage nodes, thus causing 2-bit fails. Cylindrical storage nodes, arranged as a strait type, are very apt to lean or to collapse.
To prevent leaning or the collapse of storage electrodes, either increasing the bottom CDs of storage electrodes or decreasing the height of the electrode is required. However, when the design rule of devices is defined, increasing the bottom CD to be greater than the design rule is very difficult. Also, storage nodes having a small height make it impossible to obtain desired capacitance.
Considering the above restrictions, the best way to overcome the collapse of storage nodes would be to change the arrangement of the storage nodes. The collapse of storage nodes is closely related to the very narrow interval between adjacent storage nodes that are arranged in a strait type. Accordingly, changing the arrangement or sectional shape of storage nodes may be a solution for the collapse of storage nodes. Nevertheless, changing the arrangement of storage nodes is extremely difficult in a strait-type active region structure where active regions extend in one direction.
In such a strait-type active region structure, since active regions and storage nodes naturally overlap each other on a semiconductor substrate, forming or aligning contact bodies required for electrically connecting the active regions and the storage nodes becomes very easy. However, if the arrangement of storage nodes is changed, the storage nodes and the active regions do not overlap each other. In this case, the contact bodies used for electrically connecting the storage nodes and the active regions cannot be easily formed or aligned. As a result, electrical connection between the storage nodes and the active region cannot be sufficiently secured.
Embodiments of the invention address these and other disadvantages of the conventional art.